Petroleum distillate upgrading process

Abstract

A petroleum distillate feed is upgraded and a substantial C 3 -C 4 olefin product fraction produced by contacting the feed with ZSM-5 type zeolite at (1) a temperature in the 500°-800° F. range, (2) a pressure below about 13 atmospheres gauge, and (3) an LHSV in the 0.1-15 V/V/Hr range, and fractionating the effluent product stream.

What is claimed is: 
     
       1. A process for upgrading a petroleum distillate feed consisting essentially of hydrocarbons having a normal boiling point range in the range of from about 400° to 1000° F. and producing C 3  -C 4  olefins, based upon feed converted, in an amount in the range of from about 2 to 10 weight percent, comprising producing an effluent stream containing C 3  -C 4  olefins by contacting said feed with a catalyst comprising ZSM-5-type crystalline aluminosilicate zeolite in a form which is substantially free of hydrogenation activity, said contacting being under conditions including (a) a temperature in the range of from about 500° to 800° F.; (b) a pressure below about 13 atmospheres gauge; and (c) a liquid hourly space velocity in the range of from about 0.1 to 15, said feed having a content of nitrogen-containing impurities, calculated by weight as nitrogen, below about 5 ppm. 
     
     
       2. A process as in claim 1 wherein said temperature is about 750° F., said space velocity is about 2, and said pressure is about 25 psig. 
     
     
       3. A process as in claim 1 wherein said catalyst is a composite of said zeolite and a porous binder or matrix, and said composite contains an amount of the zeolite in the range of from about 1 to 95 weight percent. 
     
     
       4. A process as in claim 1 wherein said feed has (1) a normal boiling point range in the range of from about 400° to 1000° F., (2) a sulfur-containing impurities content, calculated as sulfur, below about 20 ppm, and (3) a nitrogen-containing impurities content below about 1 ppmw. 
     
     
       5. A process as in claim 4 wherein said normal boiling point range is 500° to 800° F. 
     
     
       6. A process as in claim 1 wherein said catalyst is in a composite with a porous inorganic binder or matrix in such proportions as to contain said zeolite, in parts by weight, in an amount in the range of from about 1 to 95 percent. 
     
     
       7. A process as in claim 6 wherein said amount of zeolite is in the range 10 to 70 percent. 
     
     
       8. A process as in claim 1 wherein said zeolite is substantially in the hydrogen form. 
     
     
       9. A process as in claim 1 wherein said zeolite is ZSM-5.